<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>01_CSS显示模式</title>
    <style>
        div {
            width: 100px;
            height: 100px;
            border: 5px solid #f00;
            /*显示模式:块级元素
            默认竖着排 可以设置宽高*/
            display: block;
        }
        span {
            background-color: #ff0;
            width: 200px;
            height: 200px;
            display: inline;
            display: block;
        }
        input,button {
            width: 200px;
            height: 200px;
            display: inline-block;
        }
        .d2:hover {
            /*悬停时，元素的显示默认修改为消失
            会释放此元素占据的文档流页面布局空间*/
            display:none ;
        }
    </style>
</head>
<body>
    <div class="d1">1111</div>
    <div class="d2">2222</div>
    <div class="d3">3333</div>
    <hr>
    <span>123456789</span>
    <span>123456789</span>
    <span>123456789</span>
    <hr>
    <input type="text">
    <input type="text">
    <input type="button">
</body>
</html>